The present invention relates to apparatus for driving pipe, or similar hollow tubular structures, hereinafter referred to simply as pipes, into the ground to form an underground pipe line.
Tube driving apparatuses usually comprise some form of rigid framework which is installed into an underground excavation and hydraulic piston and cylinder units supported on the framework and connected to a pressure ring which serves to engage on a pipe to be driven. Pipes are then driven into the ground successively by operation of the units to form a pipe line. It has been found that with such an arrangement it is quite common for the pipes to partly rotate about their longitudinal axes as they are advanced. This is disadvantageous since it can result in a certain residial torsional stress being set up in the pipes. Moreover where other equipment such as conveyors or the like is to be arranged inside the pipe line further problems can arise due to the undesirable rotary motion of the pipes. Although proposals have been made to overcome this problem, including rotatably supporting the pressure ring, hitherto there has been no wholly successive means for controlling the torsional force imparted to the pipes during the driving operation.
A general object of this invention is to provide an improved form of tube-driving apparatus.